Chris Paterson is in the Scotland squad for the Rugby World Cup just months after some believed his international days were over. Photograph: Graham Stuart /Action Images

It is hardly a new phenomenon. Chris Paterson is the latest sportsperson to admit that trepidation regarding life in the potentially harsh outside world drives him towards continued rugby success.

In Paterson's case, perhaps subconsciously, there is also an element of proving people wrong. The 33-year-old forms part of Scotland's World Cup squad only months after it was reckoned his international days were over. Retirement, bluntly, petrifies him.

"Absolutely," Paterson confirms. "I think about it often, what I'm going to do post-rugby. I think about it every day and that's where the fear comes from. It's a big fear. I've not done anything else, I studied to be a PE teacher but then my working life has been this and it's different to normal life. So what you do afterwards is a big concern. I don't have any plans but I do share the fear of what happens next, I must admit."

From whatever it was born, Paterson's approach was sufficient for Andy Robinson to welcome him back into the Scotland scene.

"There's two fears," the Edinburgh player adds. "One is: 'what do you do next?' which I'm trying to address as we go, and the other one is staying too long.

"I think you're really lucky if you are in the position that you can make a decision when to stop when you're still at the top. Not many folk get that. Jason Robinson at the last World Cup final is the dream scenario, but I don't think many would get the opportunity to have that decision as to when to stop, be it form, be it injury, performance, whatever.

"These are not negative thoughts but they're human thoughts, back-of-the-brain thoughts while the front of the brain's going and doing well."

Albeit in hindsight, Paterson is adamant that the early part of this year was not a wounding period. Scotland's record points scorer – who will now take part in a national record fourth World Cup – was out of Robinson's team then, if not completely absent from the coach's thoughts.

"I think there's quite a lot of ups and downs, extremities, but as a player you focus on what you can control and that's working hard, committing yourself entirely and trusting if you work hard your reward will come. That's what I've always done," Paterson says. "I wasn't angry, never angry. Not at all. Anger is, for me, more negative. I'm determined, don't get me wrong, to get back in."

But was his pride, even briefly, hurt? "Why would it be? I had 100 caps, still felt good and was performing well for my club. What is great is I've managed to fight my way back in to this squad of 30 and then the hard work starts again if you want to be in the 15."

Robinson has played a key part in Paterson's longevity by looking to pin down a position for a player who had become used to shuffling around the back line.

"That probably helped when Andy became coach at Edinburgh," Paterson recalls. "He said: 'I see you as a full-back. There'll be times I need to play you at 10. That's fine, but I see you as a full-back.' And that was the first time in a long time I was given that direction. Trying to improve in three international positions is pretty difficult; it's hard in one but trying to pick up three is taxing."

Paterson is not exactly a relic in Scotland's party for New Zealand but the remainder of the squad has an obviously youthful look. Robinson has not named a vice-captain for the competition, but Paterson is one of the players trusted to impart words of wisdom, even if the man himself thinks few will be necessary.

"Someone asked if they look to us for advice and tips but I look to them as much as they do to me," says Paterson of the younger generation.

"I've been at World Cups before and it is different. In the Six Nations you maybe get a break but there's no break, you're in it and that's you. But these young guys have a carefree attitude, smiling face and ability to switch off on days off a lot easier than I can. I'm 33 now and the level they're playing at physically is way beyond where I was at 21."

Given a promising emergence of talent for Robinson, it would rank as a serious surprise if the coming weeks did not become Paterson's World Cup farewell as a player. He disputes any suggestion the event could pass by the younger members of the Scotland team. "I suppose if you weren't astute enough you maybe wouldn't appreciate what you were in but in New Zealand in that culture I don't think it possibly can," Paterson says.

There is no doubt, however, that Paterson will take absolutely everything in. "As a younger player, you think: 'next year this' and: 'next year that', but you get a wee bit older and you have been out of the squad … even when I've been out of the squad I'm always an enthusiastic person, it's my nature.

"I've always been determined: I want to be last off the training field, win the game of touch at the start and, no matter what age you are, that'll never change. That's my make-up but not knowing what's coming next and the appreciation you have had a good career and you want it to continue is there too."